In general, remote displays are controlled by a driver which communicates with the display by means of an electrical cable. Because electrical cables are subject to interference signals and other radiation, it is necessary to shield the cable from this outside interference. Further, the display must contain a light source or other electronics for creating a display and circuitry for receiving control signals from the driver and converting them to useable information in the display. All of this apparatus, along with the connecting cable, is relatively heavy, expensive and inconveniently complicated.
In many remote displays, and especially head-mounted displays, weight, size and expense are major factors. There is a substantial need for displays that are light, small and inexpensive.